I would say the thing I realize now that would have helped me the most was having backup of my own bodily autonomy.

Lessons of bodily autonomy can start immediately - if your young child doesn’t want to give a family member hugs/kisses/physical affection then they shouldn’t have to. Be her support in that. The trust you build with this is invaluable if someone were to cross a much larger boundary later on (such as any instance of abuse) she is much more likely to tell you or her mother that it happened because she trusts you to back her up.

Additionally you should always acknowledge her thoughts and input. Obviously kids say crazy shit that sometimes have little bearing on reality, but it is so helpful as a teenager/young adult to know that there is someone who will listen and help you process things. Just work through problems with her, and if she has a suggestion on how to solve it - even if you know it won’t work - give it a shot to SHOW her it won’t work and talk through why it happened if you can.

This is of course assuming you aren’t going to accidentally create a bomb, or otherwise cause irreversible damage to someone/thing.